"His sister was on the phone to him the night before telling him not to take the prescription medications with the sleeping tablets," he told Daily Mail Australia

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Heath Ledger (right) seen in 2007, months before he died, and his father, Kim Ledger, seen in 2010.

Heath Ledger's father says there is no one to blame for the actor's death but Ledger himself, as hard as that is to accept.

Kim Ledger opened up to Daily Mail Australia Tuesday about his son's accidental overdose in 2008, telling the publication he still feels it was Heath's own fault. "It was totally his fault. It was no one else's. He reached for them. He put them in his system. You can't blame anyone else in that situation," Kim Ledger said. "That's hard to accept because I loved him so much and was so proud of him."

The Oscar-winning actor was found face down dead in his New York apartment in January 2008 after ingesting a combination of painkillers and sleeping pills. According to his father, Ledger's sister Katie tried to warn her brother of the toxic combination.

"His sister was on the phone to him the night before telling him not to take the prescription medications with the sleeping tablets," he added. "He said, 'Katie, Katie, I'm fine. I know what I'm doing.' He would have had no idea."

Kim Ledger blames his son's fame and his hectic schedule for not allowing him to receive the proper medical care he may or may not have needed for injuries, sickness and more. "Because he was traveling a lot, he would pop in to a doctor. In the case of someone with a higher profile it's often a case of 'what do you want' instead of 'what do you need,'" he told the publication.

"There's so much pressure on them to perform so even though your body is telling you that it's not good and needs time, it's like 'just take these painkillers and keep going," he continued. "That was the case with Heath. He had to be back on set to finish [the next day]. They were doing night shoots in the freezing cold and he had a weak chest anyway. He'd caught this [cough] and just couldn't shake it but he thought he had to because he wanted to get the movie done."

Kim Ledger has spoken candidly about his son since his passing, especially after his son won a posthumous Oscar for his role as The Joker in "The Dark Knight." "Bittersweet is probably the best way I can describe that night. It was only a year and a month since his passing," he told The Hollywood Reporter in February. "We hadn't got our heads around the tragedy of losing him, but at the same time, he was receiving such accolades for what he knew was his best work."

The Oscar remains in an Australian museum in Perth with the rest of his Joker paraphernalia. Eventually, all of Heath Ledger's memorabilia will be put in the hands of his daughter Matilda, who lives with mom Michelle Williams in Brooklyn.